(display "\n========================================\n")
(define (make-frame origin edge1 edge2)
    (list origin edge1 edge2))

(define (origin-frame frame)
    (car frame))

(define (edge1-frame frame)
    (cadr frame))

(define (edge2-frame frame)
    (caddr frame))

(define frame (make-frame 1 2 3))
(display frame)
(newline)
(display (origin-frame frame))
(newline)
(display (edge1-frame frame))
(newline)
(display (edge2-frame frame))

(display "\n========================================\n")

(define (make-frame origin edge1 edge2)
    (cons origin (cons edge1 edge2)))

(define (origin-frame frame)
    (car frame))

(define (edge1-frame frame)
    (cadr frame))

(define (edge2-frame frame)
    (cddr frame))

(define frame (make-frame 1 2 3))
(display frame)
(newline)
(display (origin-frame frame))
(newline)
(display (edge1-frame frame))
(newline)
(display (edge2-frame frame))
(newline)

(display "\n========================================\n")